// SPDX-License-Identifier: GPL-2.0-or-later

  /*
   * Core driver for WM8400.
   *
   * Copyright 2008 Wolfson Microelectronics PLC.
   *
   * Author: Mark Brown <broonie@opensource.wolfsonmicro.com>

   */

  #include <linux/init.h>

  #include <linux/bug.h>

  #include <linux/err.h>

  #include <linux/i2c.h>
  #include <linux/kernel.h>

  #include <linux/mfd/core.h>

  #include <linux/mfd/wm8400-private.h>
  #include <linux/mfd/wm8400-audio.h>

  #include <linux/regmap.h>

  #include <linux/slab.h>

  static bool wm8400_volatile(struct device *dev, unsigned int reg)

  {

  	switch (reg) {
  	case WM8400_INTERRUPT_STATUS_1:
  	case WM8400_INTERRUPT_LEVELS:
  	case WM8400_SHUTDOWN_REASON:
  		return true;
  	default:
  		return false;

  	}

  }

  static int wm8400_register_codec(struct wm8400 *wm8400)
  {

  	const struct mfd_cell cell = {

  		.name = "wm8400-codec",

  		.platform_data = wm8400,
  		.pdata_size = sizeof(*wm8400),

  	};

  	return devm_mfd_add_devices(wm8400->dev, -1, &cell, 1, NULL, 0, NULL);

  }

  /*
   * wm8400_init - Generic initialisation
   *
   * The WM8400 can be configured as either an I2C or SPI device.  Probe
   * functions for each bus set up the accessors then call into this to
   * set up the device itself.
   */
  static int wm8400_init(struct wm8400 *wm8400,
  		       struct wm8400_platform_data *pdata)
  {

  	unsigned int reg;
  	int ret;

  	dev_set_drvdata(wm8400->dev, wm8400);

  
  	/* Check that this is actually a WM8400 */

  	ret = regmap_read(wm8400->regmap, WM8400_RESET_ID, &reg);

  	if (ret != 0) {
  		dev_err(wm8400->dev, "Chip ID register read failed
  ");
  		return -EIO;
  	}

  	if (reg != 0x6172) {
  		dev_err(wm8400->dev, "Device is not a WM8400, ID is %x
  ",
  			reg);

  		return -ENODEV;
  	}

  	ret = regmap_read(wm8400->regmap, WM8400_ID, &reg);

  	if (ret != 0) {
  		dev_err(wm8400->dev, "ID register read failed: %d
  ", ret);
  		return ret;
  	}
  	reg = (reg & WM8400_CHIP_REV_MASK) >> WM8400_CHIP_REV_SHIFT;
  	dev_info(wm8400->dev, "WM8400 revision %x
  ", reg);

  	ret = wm8400_register_codec(wm8400);
  	if (ret != 0) {
  		dev_err(wm8400->dev, "Failed to register codec
  ");

  		return ret;

  	}

  	if (pdata && pdata->platform_init) {
  		ret = pdata->platform_init(wm8400->dev);

  		if (ret != 0) {

  			dev_err(wm8400->dev, "Platform init failed: %d
  ",
  				ret);

  			return ret;

  		}

  	} else
  		dev_warn(wm8400->dev, "No platform initialisation supplied
  ");

  	return 0;

  }

  static const struct regmap_config wm8400_regmap_config = {
  	.reg_bits = 8,
  	.val_bits = 16,
  	.max_register = WM8400_REGISTER_COUNT - 1,

  
  	.volatile_reg = wm8400_volatile,
  
  	.cache_type = REGCACHE_RBTREE,

  };

  /**
   * wm8400_reset_codec_reg_cache - Reset cached codec registers to
   * their default values.
   */
  void wm8400_reset_codec_reg_cache(struct wm8400 *wm8400)
  {
  	regmap_reinit_cache(wm8400->regmap, &wm8400_regmap_config);
  }
  EXPORT_SYMBOL_GPL(wm8400_reset_codec_reg_cache);

  #if IS_ENABLED(CONFIG_I2C)

  static int wm8400_i2c_probe(struct i2c_client *i2c,
  			    const struct i2c_device_id *id)
  {
  	struct wm8400 *wm8400;

  	wm8400 = devm_kzalloc(&i2c->dev, sizeof(struct wm8400), GFP_KERNEL);

  	if (!wm8400)
  		return -ENOMEM;

  	wm8400->regmap = devm_regmap_init_i2c(i2c, &wm8400_regmap_config);

  	if (IS_ERR(wm8400->regmap))
  		return PTR_ERR(wm8400->regmap);

  	wm8400->dev = &i2c->dev;
  	i2c_set_clientdata(i2c, wm8400);

  	return wm8400_init(wm8400, dev_get_platdata(&i2c->dev));

  }

  static const struct i2c_device_id wm8400_i2c_id[] = {
         { "wm8400", 0 },
         { }
  };

  
  static struct i2c_driver wm8400_i2c_driver = {
  	.driver = {
  		.name = "WM8400",

  	},
  	.probe    = wm8400_i2c_probe,

  	.id_table = wm8400_i2c_id,
  };
  #endif

  static int __init wm8400_driver_init(void)

  {
  	int ret = -ENODEV;

  #if IS_ENABLED(CONFIG_I2C)

  	ret = i2c_add_driver(&wm8400_i2c_driver);
  	if (ret != 0)
  		pr_err("Failed to register I2C driver: %d
  ", ret);
  #endif
  
  	return ret;
  }

  subsys_initcall(wm8400_driver_init);